Problem: $10tu + 2tv + 9t - 9 = 6u - 4$ Solve for $t$.
Explanation: Combine constant terms on the right. $10tu + 2tv + 9t - {9} = 6u - {4}$ $10tu + 2tv + 9t = 6u + {5}$ Notice that all the terms on the left-hand side of the equation have $t$ in them. $10{t}u + 2{t}v + 9{t} = 6u + 5$ Factor out the $t$ ${t} \cdot \left( 10u + 2v + 9 \right) = 6u + 5$ Isolate the $t$ $t \cdot \left( {10u + 2v + 9} \right) = 6u + 5$ $t = \dfrac{ 6u + 5 }{ {10u + 2v + 9} }$